Along with the development of information communication equipments in the direction of high performance, high functionalization and networking, the operation signals tend to high frequency in recent years for high-speed transmission and processing of large-capacity information. Meanwhile, circuit boards are developed in the direction of high multilayer and high wiring density in order to meet the requirements on the development trends of various electronic products, which requires that the substrate materials have not only a relatively low and stable dielectric constant and dielectric loss factor to meet the requirements on high frequency transmission of signals, but also better heat resistance to meet the requirements on reliability of multilayer printed circuit boards.
CN101815734A disclosed a process for synthesizing isocyanate-modified epoxy by reacting multifunctional epoxy resin with diisocyanate compound, wherein such resin had a high softening point required by powder coatings. CN102666633A disclosed an epoxy oxazolidinone resin composition comprising divinylarene dioxide and reaction products of excessive polyisocyanate, and a curable epoxy resin composition, comprising the epoxy oxazolidinone resin composition of divinylarene dioxide derived from divinylbenzene dioxide, and polyisocyanate, at least a curing agent, and/or a catalyst. The composition had the features of low viscosity and high heat resistance.
CN1333791A disclosed a binder composition prepared from polyepoxide, polycyanate and chain extender, wherein such composition was advantageous to enhance the adhesiveness between copper foil and laminate.
CN101695880A disclosed a process for preparing polyoxazolidinone laminates, comprising reacting diisocynate with epoxy in the presence of imidazole catalyst to produce polyoxazolidinone, then preparing laminates by using the resultant polyoxazolidinone, wherein the prepared laminates had better mechanical strength and heat resistance.
JP2003-252958 disclosed obtaining cured products having a reduced dielectric loss factor by using biphenyl epoxy resin and active ester curing agent. Since the epoxy resin used therein was bifunctional, it had a low crosslinking density with active ester curing agent, and the condensate thereof had a low glass transition temperature.
Although the aforesaid patents disclosed that isocyanate-modified epoxy or polyoxazolidinone itself and the composition thereof had better adhesiveness, heat resistance and tenacity, but they had the defects such as worse moisture and heat resistance, lower reliability, and relatively higher dielectric loss factor, so as to limit the application in high-speed materials.